Wildfire Smoke Alert: Toronto ranked in top 10 most polluted cities

Is the air quality good in the Great Lakes Region and Canada?

As of July 16, 2025, there is poor air quality due to wildfire smoke across many U.S. states and Canadian provinces, mostly in the lower Great Lakes region.

Smoke is contributing to poor air quality ranging from the “moderate” to “unhealthy” range in Illinois, Indiana, Maine, Michigan, Minnesota, Ohio, New York and Vermont.

In Canada, poor air quality is unhealthy in major cities across Alberta, Ontario, and Quebec, as well as Alberta and parts of Manitoba and Saskatchewan. As of the morning of July 16, Toronto, Canada was the ninth most polluted major city in the world. Montreal, Canada was the 11th and Detroit, Michigan was the 13th. For a more detailed look, see Toronto's air quality map.

Ranked list of most polluted major cities on Wednesday morning. Source: IQAir.

Which major cities are most affected by the poor air quality today?

Major cities affected by wildfire smoke in Ontario, Quebec, and the Great Lakes region include:

Buffalo, New York
Cleveland, Ohio
Detroit, Michigan
Montreal, Quebec
Quebec City, Quebec
Saskatoon, Saskatchewan
Toledo, Ohio
Toronto, Ontario

What is causing poor air quality in the Great Lakes Region and Canada?

Widespread wildfires across northern Canada and shifting wind direction has sent smoke southeast towards the Great Lakes Region and the St. Lawrence River.

Are there any alerts in place?

The National Weather Service has issued air quality alerts for southeast Michigan, northeastern Illinois, northern Maine, central Ohio, and northeastern Indiana (1).

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